An endonuclease is an enzyme that catalyzes the hydrolysis of phosphodiester linkages within a nucleotide chain. Endonucleases have been widely used for the creation of recombinant DNA molecules, mapping mutations and for studying the interactions of DNA with various intercalating agents. Certain types of endonucleases are highly selective for a specific nucleic acid recognition sequence or for a single-stranded region within double-stranded nucleic acid.
Nucleases are critical to the successful execution of nearly all DNA damage responses. In particular, these enzymes recognize and excise specific forms of genetic damage, or minimally, initiate removal of a lesion-containing DNA strand. As damage excision is essential for the maintenance of genetic integrity for cells to include bacterial and neoplastic cells, altering the activity of Apurinic/Apyrimidinic endonuclease (APE) could hold promise for enhanced or novel treatments to infection and cancer.
The utility of single-strand-specific nucleases as analytical tools has been widely recognized and has led to their extensive application as probes for the determination of nucleic acid structure. The technology described in this invention will not only dramatically increase the sensitivity of quantitating endonuclease activity, but will duly allow for enzyme substrate characterization.